KR900004352B1 - Vehicle suspension system - Google Patents

Abstract

A vehicle suspension system includes a wheel hub on which a wheel is rotatably mounted and a pair of lateral link transversely extending and disposed in a spaced relationship with each other in the longitudinal direction of the vehicle. The lateral link is pivotally connected to the vehicle body at the inner end and to the wheel hub at the outer end so that the wheel hub can be swingably moved in the vertical direction relative to the vehicle body. At least one of the lateral links is divided into inne and outer link members. The inner link member is connceted to the outer link member by a connector including a precompressed resilient member constituted to be deflected in the axial direction of the lateral links when the compressive force is applied to the resilinet member beyond the precompressed force so as to reduce the length of the lateral link member.

Description

Suspension of car

1 is a plan view showing an example of a suspension to which the first embodiment of the present invention is applied.

2 is a graph showing examples of deformation characteristics of a lateral link system before and after each of which obtains the characteristics as shown in FIG.

3 is a graph showing an example of a characteristic line according to the present invention.

4 is a plan view showing the behavior change of the rear wheels based on the characteristics according to the first embodiment of the present invention.

5 is an enlarged cross-sectional view showing a coupling portion between the inner link and the outer link.

6 shows an example of a bush, the cross-sectional view in the radial direction thereof.

FIG. 7 is a cross-sectional view taken along line 6 of FIG.

8 is a plan view showing one example of the suspension acted on the second embodiment of the present invention.

9 is a graph showing an example of the characteristic lines of the second embodiment of the present invention.

10 is a plan view showing a change in the behavior of the rear wheels based on the characteristics according to the second embodiment of the present invention.

FIG. 11 is a graph showing examples of deformation characteristics of the lateral link system before and after obtaining the characteristics as shown in FIG.

12 is an enlarged cross-sectional view showing a coupling portion between an inner link and an outer link.

Figure 13 is an enlarged cross-sectional view of another embodiment showing the engaging portion of the inner link and the outer link.

* Explanation of symbols for main parts of the drawings

1: Bezoframe 2R, 2L: Suspension

3R, 3L: Rear wheel 4R, 4L: Front lateral link

4R.1,5R.1: Inner Link 4R.2,5R.2: Outer Link

4R.3,4R.3: Coupling region 5R, 5L: Rear lateral link

6R, 6L: Hub 8R, 8L: Front bush

12R, 12L: Front bushing 10R, 10L: Rear bushing

14R, 14L: Rear bush 15R, 15L: Spindle (center of rotation)

41: cylinder 41a: stopper

42: piston 45: spring

α ₁ , β _l : Bending point 1: predetermined displacement

The present invention relates to a suspension of an automobile made for toe control of a wheel.

In recent years, in the suspension of automobiles, wheels, in particular, rear toe control is performed, and a lot of intentions are made for the vehicle body to exhibit desirable behavior in accordance with the running state.

During the toe control of the rear wheels, in the relationship with the lateral force acting on the rear wheels, the ratio of change of the rear wheels in the toe in direction according to the lateral force is smaller than in the case of small lateral forces. (See Japanese Patent Application Laid-Open No. 60-148708). That is, the rear wheels are attached to the vehicle body vertically via a pair of lateral links disposed at the front and rear of the center of rotation of the rear wheels, and the bushes are interposed at the connection portion of the lateral links to the body side or the rear wheel side. The toe control described above can be obtained by setting the deformation characteristic of to be different between the front lateral link and the rear lateral link. In this way, when the lateral force becomes very large, such as when turning sharply or in a lane disease at high speeds, the rear wheels are relatively toe-inward, thereby increasing the grip force of the rear wheels and improving the steering stability. When the lateral force is small, that is, at low or medium speeds, it is also referred to as turning or migrating. And in such a thing, the characteristic line which shows the amount of tow change of a wheel with respect to a lateral force is made to have one bending point (characteristic change point).

As described above, in the conventional tow control of the rear wheels in accordance with the lateral force, the tow control is performed in the direction in which the steering stability improves as the lateral force increases, that is, the toe-in direction, which further ensures the stability of the steering. It also comes from the idea of being related. In other words, securing straightness and steering stability are common in that the rear wheels are relatively toe to raise the grip force of the rear wheels, and the grip body is not bent to increase the grip force.

However, the linear stability in the case of performing the toe control of the rear wheels in accordance with the lateral force as in the conventional art, in particular, the linear stability at high speed is not necessarily satisfactorily satisfied.

The reason for this is that the straightness stability is not satisfactorily satisfied.The lateral force acting on the rear wheels in the area to obtain steering stability along with the large change of the body, such as during sharp turn or lane change, is continuously high speed. It can be seen that they are far from the magnitude of the lateral force when driving straight. In other words, it was found that in the straight traveling at high speed, the lateral force acting on the rear wheel is in a region smaller than the magnitude of the lateral force at the time of turning capability required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in the tow control of the rear wheels according to the lateral force, as in the prior art, while improving the swingability when the lateral force is relatively small and securing the stability of the steering when the lateral force is relatively high It is to provide a suspension of a vehicle to improve the straightness stability when the lateral force when the operation is very small.

In order to achieve the above object, the present invention considers that the lateral force acting on the rear wheel in the driving state where straightness stability is particularly required as described above is smaller than the lateral force acting on the rear wheel in the driving state in which rotationality is required. Thus, the toe control of the rear wheels by the magnitude of the lateral force is divided into three areas, the area for straightness stability, the area for turning stability, and the area for adjustment stability, in the order from the smaller side to the larger side. have. Specifically, the rear wheels are supported up and down on the vehicle body via a pair of lateral links arranged in front and rear of the center of rotation, and the bushes are interposed in the connecting parts to the body and rear wheels of each lateral link. In the suspension of a vehicle made up, the rear lateral link is configured by coupling the inner link and the outer link by a predetermined amount in a direction in which the spring is compressed in a direction in which the spring is compressed, respectively, the bush The deformation characteristics of the lateral force between the front lateral link system and the rear lateral link system, which are different from each other, are set differently, and the tow variation of the rear wheel with respect to the lateral force is shown by the difference of the deformation characteristics of the front and rear lateral link systems. When the characteristic line is small when the lateral force is small and when the lateral force is medium when the lateral force is large On the contrary, the ratio of change of the rear wheels in the toe-in direction is increased as the lateral force increases.

As described above, since the characteristic line representing the amount of change in the toe of the rear wheel with respect to the lateral force had only one bend point in the first embodiment, the second embodiment of the present invention had two bend points. By making it satisfy | fill, the rear wheel grip force becomes relatively high also in the area | region where the lateral force is smaller than this, and the linear stability and steering stability can be acquired. That is, if the bending point of the side with the smallest lateral force is called the first bending point and the bending point of the side with the larger lateral force is the second bending point, when the lateral force until the first bending point is small according to the increase of the lateral force, it is straight ahead. It becomes a tow control area that ensures stability, and when the lateral force from the first bend point to the second bend point is medium, it becomes a tow control area that secures turnability, and when the lateral force after the second bend point is large, the steering stability It becomes a toe control area secured.

More specifically, when the lateral force requiring straightness is small (for example 0.2 to 0.3G) and when the lateral force requiring preference is moderate (for example, 0.4 to 0.5G), the lateral force for steering stability is required. In this case (for example, 0.5G or more), since the ratio of change of the rear wheel to the toe-in direction due to the increase in the lateral force is large, the straightness and the steering stability can be secured while securing the turning ability when the lateral force is medium. have.

In addition, in the present invention, the inner link and the outer link are coupled to the intermediate portion of the rear lateral link, that is, the predetermined amount of the rear link, rather than the bush, which is interposed between the lateral links of the rear wheels and the body parts of the rear wheels. In order to obtain the bending point of the characteristic line for the tow control as described above by using a spring installed separately in the compressed state in advance, in other words, the deformation characteristics of the bush interposed mainly to secure the riding comfort Since it is not necessary, the setting for toe control can be performed easily and reliably, and the freedom of the setting is also high.

In addition, the present invention, the wheel support member for supporting the wheels and the rotational support, and the wheel support member is connected vertically and vertically with respect to the vehicle body and generally extends in the vehicle width direction to be spaced apart by a predetermined distance in the front and rear direction of the vehicle body and the inner end A suspension of a vehicle having a pair of lateral links in which a pivot is mounted rotatably and an outer end is pivotally mounted on the wheel support member, wherein at least one of the pair of lateral links is divided in the middle so that the inner link and the outer link are separated. A compressive force is applied between the inner link and the outer link, and the load in the link axis direction and the direction in which the inner link and the outer link are close to each other is interposed between the inner side and the outer link. When the elastic member is deformed to exceed the link length characterized in that configured Is to provide the car's suspension.

In addition, according to the present invention, the rear wheels are supported up and down on the vehicle body via a pair of lateral links disposed at the front and rear of the center of rotation thereof, and the bushes are connected to the vehicle body and rear wheels of each of the steering links, respectively. In the suspension of a vehicle interposed therebetween, the rear lateral link is configured by combining the inner link and the outer link by a predetermined amount relative to the predetermined direction in the direction in which the spring is compressed through a spring to which the axial force is applied. And the deformation characteristics of the lateral force of the front lateral link system and the rear lateral link system respectively including the bush are set differently, and the toe of the rear wheel with respect to the lateral force is different by the difference of the deformation characteristics of the front and rear lateral link systems. When the characteristic line indicating the amount of change is small and the lateral force is large, the lateral force is medium. Compared to the drawing, the change ratio in the toe-in direction of the rear wheels is increased according to the increase in the lateral force.

EMBODIMENT OF THE INVENTION Hereinafter, 1st Example of this invention is described based on attached drawing.

FIG. 1 is a schematic diagram showing an example in which the first embodiment of the present invention is applied to a rear wheel of an FF vehicle. Since the suspension structure of the right and left rear wheels is the same structure, the following description will be given of the suspension for the right rear wheel. For the left rear wheel suspension, the "L" subscript is used instead of the "R" subscript attached to the right rear wheel component, and the overlapping description is omitted.

In FIG. 1, reference numeral 1 denotes an auxiliary frame fixed to the vehicle body by weight of the upper part of the spring, and the right rear wheel 3R is connected to the auxiliary frame 1 via a right arm suspension 2R of swinging arm type. It is supported up and down.

The suspension 2R has, respectively, a rear lateral link 5R extending in the vehicle width direction, a front lateral link 4R partitioned as described later, and a hub 6R as a wheel support member extending in the front and rear directions of the vehicle body. have. The inner end of the front lateral link 4R (inner-width direction inner end) is pivotally connected to the support shaft 7R protruding from the auxiliary frame 1 via the bush 8R, and the rear lateral link ( The inner end portion (the vehicle width direction inner end portion) of 5R is pivotally connected to the support shaft 9R protruding from the auxiliary frame 1 via the bush 10R. The outer end portion of the front lateral link 4R is pivotally connected to the support shaft 11R protruding from the diagnostic portion of the hub 6R via the bush 12R, and the rear lateral link 5R The outer end is pivotally connected to the support shaft 13R protruding from the rear end of the hub 6R via the bush 14R. The spindle 15R protrudes from the outer end of the hub 6R, and the right rear wheel 3R is rotatably supported around the spindle 11R.

The front and rear lateral links 4R and 5R are disposed substantially parallel to each other, and the spindle 15R is disposed at an intermediate portion in the front-back direction with the bushes 12R and 14R at each outer end thereof. By doing in this way, the lateral force input to the rear wheel 3R is equally divided into the lateral links 4R and 5R before and behind, and is input. The support shafts 7R, 9R, 11R, 13R, and bush 8R, 10R, 12R, and 14R extend their axes in their front and rear directions, respectively, so that the right rear wheel 3R is It swings around up and down about the support shaft 7R (9R). The rear end shoe of the tension rod 17R extending almost in the front and rear direction of the vehicle body is pivotally connected to the support shaft 16R protruding from the inner end of the hub 6R via the bush 18R. The front end portion of the 17R is pivotally connected to the support shaft 20R protruding from the vehicle body via the bush 19R. Of course, the two bushes 18R and 19R extend in the vehicle width direction, and the rigidity of the hub 6R in the front and rear directions is secured by the tension rod 17R.

In addition, the hub 6R is connected to the lower end of the strut 27R made of a hydraulic shock absorber and elastic rubber or coil spring, as is already known.

The front lateral link 4R is formed by combining the inner link 4R.1 and the outer link 4R.2 formed separately from each other, as described later, and the inner and outer links 4R.1 and 4R.2. As described later, the coupling portion 4R.3 is interposed with a spring compressed in advance. In addition, the deformation characteristics of the front lateral link 4R system including the springs in addition to the bushes 8R and 12R are shown in FIG. 2 (F), and the rear lateral link including the bushes 10R and 14R (FIG. 2). 5R) Deformation characteristics of the system are indicated by the (R) line in FIG.

FIG. 5 shows a detailed view of the engaging portion 4R.3 in the front lateral link 4R.

In Fig. 5, the outer end of the inner link 4R.i is formed integrally with a cylinder 41 that opens outward in the vehicle width direction. In addition, the inner end of the outer link 4R.2 is integrally formed with a large-diameter piston 42 which is slidably fitted into the cylinder 4l. The piston 42, that is, the outer link 4R.2, is prevented from being separated through the elastic member 44 by the cover member 43 screwed to the cylinder 41, that is, the inner link 4R.1. ), The outer link 4R.2 is prevented from falling more than a predetermined distance. In addition, the outer link 4R.2 is urged toward the rear wheel 3R by the spring 45 (coil spring in this embodiment) disposed in the compressed state in the cylinder 41.

In other words, by adjusting the screwing position of the cover member 43 with respect to the cylinder 41, the extrusion force of the spring 45, ie, the compression force compressed beforehand, is adjusted. By doing so, with respect to the external force that causes the front lateral link 4R to compress, initially against the large force by the pre-compressed spring 45, if the external force is greater than the pre-compressed compression force, the spring 45 Compression (compression of the front lateral link 4R) is carried out in the form according to the elastic modulus.

Each bush 8R, 10R, 12R, 14R is an inner cylinder 21 into which the support shafts 7R, 9R, 11R, 13R are fitted, as shown in FIG. 6, FIG. ) And the outer cylinder 22 to which the front and rear lateral links 4R and 5R are coupled, and the rubber member 23 interposed between the inner and outer cylinders 21 and 22, but the rubber member 23 Is set to a predetermined hardness. First, since the bushes 12R and 14R at the outer ends of the lateral links 4R and 5R are filled with rubber materials 23 having the same hardness, the two bushes 12R and 14R are provided. The relationship between the load (lateral force) and the amount of deformation thereof is the same. In the bush 8R at the inner end of the front lateral link 4R and the bush 10R at the inner end of the rear lateral link 5R, the front bush 8R is harder than the rear bush 10R. .

According to the above configuration, the deformation characteristic of the front lateral link 4R system with respect to the load (lateral force) is the same as the line 2 (F), and the deformation characteristic of the rear lateral link 5R system is shown in FIG. It becomes like R) line. That is, the characteristic line F has one bending point (characteristic change point) (alpha), and the deformation | transformation becomes small (hardness) in the range which load (lateral force) becomes smaller than ((alpha), and exceeds ((alpha)). After that, the deformation is set to be large (flexible).

In addition, the characteristic line R becomes almost linear. In the embodiment, both characteristic lines F and R are interchanged at one point, and when the load is less than the intersection, the deformation amount of the front lateral link 4R system is smaller than the deformation amount of the rear lateral link 5R system. If this is larger than the intersection point, the deformation amount of the front lateral link 4R system becomes larger than the deformation amount of the rear lateral link 5R system. Of course, the load at the bending point α corresponds to the precompressed compression force of the spring 45 at the front lateral link 4R. Incidentally, the inclination from the origin of the characteristic line F to the bending point α depends on the characteristics of the bush 8R.

This is caused by the difference in deformation characteristics of the lateral link 4R and 5R systems before and after described above. The relationship of the toe change amount of the right rear wheel 3R to the magnitude of the lateral force acting on the right rear wheel 3R is indicated by the characteristic line C of FIG. 2, and other representative examples of the characteristic line obtained by the present invention are (a is shown as (b) (c) (d) (e).

Based on the characteristic line C shown in FIG. 3, the behavior change of the right rear wheel 3R is demonstrated by FIG. In FIG. 4, the lateral force is indicated by (F), and the posture change of the right rear wheel 3R is represented by the solid line when the lateral force F is "0", and the lateral force F is "small". The dashed line also indicates when the lateral force F is "cle" in broken lines. Further, 0 _{1 to} 0 ₄ are the widthwise center lines of the right rear wheel 3R, when 0 ₁ is the lateral force "0", when 0 ₂ is the lateral force "small", and 0 ₃ is the lateral force "large" Is displayed. In addition, the spring 45, the bush 8R, etc. are typically represented by the shape of a spring.

As is also apparent from this fourth figure, when the lateral force F is zero, the right rear wheel 3R is pointing straight ahead. When the lateral force F is small, since the deformation amount of the front lateral link 4R system is smaller than the deformation amount of the rear lateral link 5R system, the right rear wheel 3R tends to toe out, and the straightness is stable. It is possible to maintain an appropriate balance of control and controllability. Moreover, when the lateral force F is "large", since the deformation amount of the rear lateral link 5R system is smaller than the deformation amount of the front lateral link 4R system, the right rear wheel 3R is when the lateral force F is "small". In addition, the tow lifting amount is increased, and the steering stability can be improved. In other words, the increase in the tow lift becomes stronger in the steering characteristic than when the tow lift is "small". Of course, all of the above is also true for the left rear wheel 3L.

Although the embodiment has been described above, the present invention can be similarly applied to a rear wheel drive vehicle.

In addition, the present invention can be similarly applied to a suspension of an appropriate type as long as it has lateral links before and after. For example, the lateral links 4R and 5R in front and rear in FIG. 1 have their inner side widthwise ends wider than their outer ends, and the upper arm extending in the vehicle width direction further toward the hub 6R (rod shape). Alternatively, the shape is not a problem, such as type A, so-called double wish. In the multi-link system, the tension rod 17R (tray link arm) extending in the front and rear directions of the vehicle body may be formed in a panel shape so that the rigidity in the vehicle width direction is small and the rigidity in the vertical direction is increased.

The present invention can also be applied to the front wheels, in which case the configuration of the front and rear lateral links 4R and 5R is opposite to that shown in FIG. 1, i.e., the rear lateral links 5R in advance. It is good to have a split type with the compressed spring 45. Of course, in this case, the characteristic line which shows the amount of change of the tow of the front wheel with respect to the lateral force becomes a shape so that it may become up-down symmetry with the thing of FIG.

As apparent from the foregoing, the present invention achieves a characteristic that satisfies the two conditions of securing stability when the lateral force is large while maintaining the balance of straightness stability and maneuverability when the lateral force is small. Since the one side of the cross section is divided into a pre-compressed spring interposed in the divided part, the deformation characteristics of the bush installed in the connection portion of the lateral link to the vehicle body side or the wheel side need not be particularly complicated. The bush can be installed easily and reliably like a desired characteristic and has a high degree of freedom for installation.

FIG. 8 is a schematic diagram showing an example in which the second embodiment of the present invention is applied to the rear wheel of an FF car, and in FIG. 8, (1) is an auxiliary frame fixed to the vehicle body as a weight on a spring part, The right rear wheel 3R is supported by the beam frame 1 via the swing arm type right suspension 2R.

The suspension R each has a front lateral link 4R extending in the vehicle width direction, a rear lateral link 5R partitioned as described later, and a hub 6R serving as a back support member extending in the front and rear directions of the vehicle body. have.

The inner end portion (the vehicle width direction inner end portion) of the front lateral link 4R is pivotally connected to the support shaft 7R protruding from the auxiliary frame 1 via the bush 8R, and the rear lateral link ( The inner end portion (the vehicle width direction inner end portion) of 5R is pivotally connected to the support shaft 9R protruding from the auxiliary frame 1 via the bush 10R. The outer end of the front lateral link 4R is pivotally connected to the support shaft 11R protruding from the dun end of the hub 6R via the bush 12R, and the rear lateral link 5R The outer end is pivotally connected to the support shaft 13R protruding from the bullet section after the hub 6R via the bush 14R. The spindle 15R protrudes from the outer end of the hub 6R, and the right rear wheel 3R is rotatably supported about the spindle 15R.

The front and rear lateral links 4R and 5R are disposed substantially parallel to each other, and the spindle 15R is disposed at an intermediate portion in the front and rear direction with the bushes 12R and 14R at each outer end thereof. By doing so, the lateral force input to the rear wheels 3R is input in substantially equal parts to the front and rear lateral links 4R and 5R. The support shafts 7R, 9R, 11R, 13R, and bush 8R, 10R, 12R, and 14R extend their shaft centers in the vehicle body front and rear directions, respectively, so that the right rear wheel 3R is It swings around up and down about the support shaft 7R (9R). The support shaft 16R protruding from the inner end of the hub 6R secures the rigidity of the hub 6R in the front-rear direction by the tension rod 17R extending almost in the front-rear direction.

In addition, the lower end part of the support | pillar 27R which consists of a hydraulic shock absorber, elastic rubber, or a coil spring is connected to the virtual part 6R as already known.

The rear lateral link 5R is constituted by combining the inner link 5R.1 and the outer link 5R.2 formed separately from each other as described below, and the inner and outer links 5R.1 and 5R.2. The joint with is indicated as (5R.3).

This coupling portion 5R.3 shows the deformation characteristics of the front lateral link 4 system including the bushes 8R and 12R, interleaved with pre-compressed springs, as described below. In addition, deformation characteristics of the rear lateral link 5R system including the spring in the bushes 10R and 14R are indicated by the (R) line in FIG.

FIG. 12 shows a detailed view of the engaging portion 5R.3 in the rear lateral link 5R.

First, the inner side link 5R.1 is formed in one piece with a cylinder 41 that opens outward from the outer end thereof in the vehicle width direction. In addition, the inner end of the outer link 5R.2 is integrally formed with a large-diameter piston 42 which is slidably fitted into the cylinder 41. The piston 42, i.e., the outer link 5R.2, is prevented from being separated through the elastic member 44 by the cover member 43 screwed to the cylinder 41, i.e., the inner link 5R.1. ), The outer link 5R.2 is prevented from falling more than a predetermined distance.

In addition, the outer link 5R. 2 is urged toward the rear wheel 3R by the spring 45 (coil spring in this embodiment) disposed in the compressed state in the cylinder 41. In other words, by adjusting the screw engagement position with respect to the cylinder 41 of the cover member 43, the compression force of the spring 45, ie, the compression force previously compressed, is adjusted.

By doing so, the external force for compressing the rear lateral link 5R is initially opposed by a large force by the pre-compressed spring 45, and when the external force becomes larger than the pre-compressed compression force, the spring 45 Compression (compression of the rear lateral link 5R) is carried out in the form according to the elastic modulus.

Then, when the spring 45 begins to be compressed and the outer link 5R.2 is displaced relative to the inner link 5R.1 by the predetermined displacement l, the piston 42 stops ( 41a), the rear lateral link 5R is regulated to be compressed further after this contact.

Each bush 8R, 10R, 12R, 14R has an inner cylinder 21 into which the support shafts 7R, 9R, 11R, 13R are fitted, as shown in FIGS. 6 and 7. And the outer cylinder 22 to which the lateral link 4R and 5R are coupled, and the rubber member 23 interleaved between the inner and outer cylinders 21 and 22, but the rubber member 23 has a predetermined value. It is set to longitude.

First, since the bushes 12R and 14R at the outer ends of the lateral links 4R and 5R are filled with rubber materials 23 having the same hardness, the two bushes 12R and 14R are provided. The relationship between the load (lateral force) and the amount of deformation thereof is the same. In the bush 8R at the inner end of the front lateral link 4R and the bush 10R at the inner end of the rear lateral link 5R, the front bush 8R is more flexible than the rear bush 10R. .

As described above, the load (lateral force) of the front lateral link 4R system is due to the difference in setting the deformation characteristics of the bushes 8R and 10R and the configuration of the rear lateral link 5R via the spring 45. Deformation characteristics for Fig. 11 are the same as those in Fig. 11F, and the rear lateral link 5R system deformation characteristics are the same as in Fig. 11R. That is, the characteristic line R has two bending points α1 (β), and its deformation is small (hard) in a range where the load (lateral force) is smaller than (β1), and deformation exceeds (β1). It becomes larger (flexible) and is set so that the deformation becomes smaller again (harder) after exceeding (a1). In addition, the characteristic line F becomes a substantially linear thing. Both characteristic lines (F) (R) change at two points, r1 and r1 and r2, and when the load is less than Rr1 and greater than r2, the deformation amount of the front lateral link 4R system is the rear lateral link 5R. When the load is greater than the deformation amount of the system and the load is between r1 and r2, the deformation amount of the front lateral link 4R system is smaller than the deformation amount of the rear lateral link 5R system. Of course, it corresponds to the pre-compressed compression force of the spring 45 in the rear lateral link 5R of the load at the bending point β1. Incidentally, the inclination from the origin of the characteristic line R to the bending point β1 and the inclination after the bending point α1 depend on the characteristics of the bush 12R (or 14R).

As the deformation characteristics of the lateral link 4R and 5R systems before and after described above are different, the relationship between the amount of change in the tow of the right rear wheel 3R and the magnitude of the lateral force acting on the right rear wheel 3R is shown in FIG. It is shown by the characteristic line X, and ((alpha) 1, (beta) 1, (gamma) 1, (gamma) 2) in 9 degree | times correspond to the thing of FIG. 3, respectively.

Based on such characteristic line X, the behavior change of the right rear wheel 3R will be described with reference to Fig. 19-0. In Fig. 10, the lateral force is denoted by F, and the right rear wheel 3R is shown. The posture change in the horizontal line when the lateral force (F) is "0", the dashed line when the lateral force (F) is "small", the dashed line when the lateral force (F) is "medium", and the lateral force When (F) is "cle", it shows with a broken line. 0 _{1 to} 0 ₄ are the axial center lines of the right rear wheel 3R, 0 ₁ is when the lateral force is "0", 0 ₂ is when the lateral force is "small", and 0 ₃ is when the lateral force is "middle". , 0 ₄ indicates when the lateral force is "cle".

In addition, bush 8R (10R) is typically represented by the shape of a spring, In the 2nd Example, each member of each member is applied so that the lateral force F may act equally with respect to this bush 8R (10R). The dimensions are set.

As is apparent from FIG. 10, when the lateral force F is zero, the right rear wheel 3R is pointing straight ahead. When the lateral force F is small, the amount of deformation of the front lateral link 4R system is the rear lateral link. Since it is larger than the deformation amount of the (5R) system, the right rear wheel 3R becomes a toe-in, and the straight stability is secured. Moreover, when the lateral force F is "medium", since the deformation amount of the rear lateral link 5R system is larger than the deformation amount of the front lateral link 4R system, the right rear wheel 3R has a small lateral force F. The tow lifting amount is reduced (reduced) more than ever, so that the grayness, or maneuverability, can be improved.

That is to say, the tow lifting is alleviated, the understeering characteristic is weaker than when the tow lifting is "large", and the direction of the vehicle to bend the steering wheel is improved. In addition, when the lateral force is "large", the right rear wheel 3R is displaced in the toe-in direction again, and the steering stability is secured strongly in the understeering tendency at the time of sudden turning or when changing the fast lane.

Of course, the above is also true for the left rear wheel 3L.

Here, the characteristic line X which shows the tow change amount of the rear wheel 3R (or 3L) with respect to the lateral force F can be variously deformed according to a vehicle model etc. as shown by the broken line in FIG. The two bending points are indicated by black dots. Also in the characteristic line indicated by the broken line, the rate of change in the toe-in direction due to the increase in the lateral force (the toe-out can be regarded as a negative toe-in) is smaller than the other part between the two bending points.

FIG. 13 is a view showing another embodiment of the engaging portion 5R.3 of the inner link 5R.1 and the outer link 5R.2, and its operation is the same as that of the first and second embodiments. The description is omitted. In this case, however, the elastic rubber 53 is used instead of the coil springs 45 of the first and second embodiments, and the cylinder is composed of a cylinder case 51 and a cap 52, and the cylinder case 51 and It is a point comprised between the cap 52 and the piston 42 interposed two resin bushes 54.

Although the second embodiment has been described above, the present invention can be similarly applied to a rear wheel drive vehicle. In addition, the present invention can be similarly applied to a suspension of an appropriate type as long as it has lateral links before and after. For example, the front and rear lateral links 4R and 5R in FIG. 8 have their inner side ends wider than the outer ends, and the upper arm (rod shape) extending further in the vehicle width direction with respect to the hub 6R. Alternatively, the same applies to the so-called double wish bone type (multi-link type) in which the shape of the A type is not a problem).

In the multi-link system, the tension rod 17R (tray link arm) extending in the front-back direction of the vehicle body may have a panel shape such that the rigidity in the vehicle width direction is small and the rigidity in the vertical direction is increased.

According to the present invention, as is apparent from the above description, the driving stability satisfies all three conditions: securing straight stability when the lateral force is small, securing frosting when the lateral force is medium, and securing steering stability when the lateral force is large. The behavior of the vehicle can be made optimal.

In order to obtain the characteristic satisfying the above three conditions, the rear lateral link is used as a split type so that a pre-compressed spring interposed in this divided part is used. It is not necessary to make the deformation | transformation characteristic of the mounted bush especially complicated, and it can be set easily and surely like a desired characteristic, and also has high freedom of setting.

Corresponding reference numerals of the components of the present invention described in the claims describe only the symbols of the right (R) component, and the symbols of the left (L) component whose function is the same as the right component are not described for convenience.

Claims (16)

The wheel support member 6R for supporting the wheels in rotation and the wheel support member 6R are connected vertically and vertically with respect to the vehicle body. The wheel support member 6R extends in the vehicle width direction and is spaced apart by a predetermined distance in the front and rear direction of the vehicle body. In the suspension 2R of a vehicle having a pair of lateral links 4R and 5R mounted at a rotatable end and mounted at an outer end to the wheel support member 6R, respectively, the pair of lateral links At least one of 4R and 5R is divided in the middle and separated into inner links 4R.1 (5R.1) and outer links 4R.2 and 5R.2, respectively, and the inner ranks 4R.1 Between the 5R.1 and the outer links 4R.2 and 5R.2, an elastic member is applied to the connection side end in advance so that the inner link 4R.1 and 5R. 1) the elasticity when the load in the direction in which the outer links 4R.2 and 5R.2 approach each other exceeds the precompressed compressive force. Material transformation by the suspension of the vehicle, characterized in that configured such that a shorter link length. A piston 42 extending in the radial direction is installed at one of the connection side ends of the inner links 4R.1, 5R.1 and the outer links 4R.2, 5R.2. And a cylinder (41) for fitting the piston (42) on the other connection side end portion. The end portions of the pair of lateral links 4R and 5R are rotatably mounted on the wheel support member 6R or the vehicle body via rubber bushes 8R, 12R and 10R and 14R, respectively. Suspension of the car, which has become. 2. The pair of lateral links (4R, 5R) according to claim 1, characterized in that the front link (4R) disposed in front of the center of the wheel and the rear link (5R) disposed behind the center of the wheel. Suspension of the car. 3. The suspension of an automobile according to claim 2, wherein a restricting means for restricting the displacement in the direction in which the piston (42) falls out is installed behind the piston (42). 3. Suspension of a vehicle according to claim 2, wherein the piston (42) is configured such that its circumferential portion slides and displaces the inner wall surface of the cylinder (41). 6. The suspension of an automobile according to claim 5, wherein the restricting means is a cover member (43) which is screw-fixed to the cylinder tip. The vehicle suspension according to claim 1, wherein the elastic member is installed in a pre-compressed state between the bottom wall portion of the cylinder (41) and the front wall surface portion of the piston (42). The suspension of an automobile according to claim 8, wherein the elastic member is made of a coil spring. The suspension of an automobile according to claim 8, wherein said elastic member is elastic rubber (53). 3. Suspension of a vehicle according to claim 2, characterized in that there are control means for controlling the displacement amount in the proximal direction of the piston (42) with respect to the cylinder (41) to a predetermined value. The vehicle suspension according to claim 11, wherein the control means is configured by making the radial dimension of the piston (42) larger than the dimension of the inner diameter of the cylinder (41). 12. The suspension of a vehicle according to claim 11, wherein said control means comprises a stopper (41a) formed on the inner wall of said cylinder. The vehicle suspension according to claim 1 or 4, characterized in that the rear lateral link (5R) is divided. The vehicle suspension according to claim 1 or 4, wherein the front lateral link (4R) is divided. The rear wheels 3R are supported up and down on the vehicle body via a pair of lateral links 4R and 5R arranged at the front and rear of the center of rotation thereof, and the rear wheels 3R are connected to the vehicle body side and the rear wheel side of each steering wheel. In the suspension 2R of a vehicle in which bushes 8R, 10R, 12R, and 14R are interposed, respectively, the rear lateral link 5R is configured in advance of the inner link 5R.1 and the outer link 5R.2. The front lateral link (4R) system and the rear, each of which comprises the bush, are configured by engaging and disabling by a predetermined amount in the direction of compressing the spring 45 via a spring 45 provided with a compression force. The deformation characteristics with respect to the lateral force of the lateral link 5R system are set differently, and the toe change amount of the rear wheel with respect to the lateral force F is displayed by the difference of the deformation characteristics of the lateral links 4R and 5R systems before and after. The characteristic line to say is that the lateral force (F) When the lateral force is large when the lateral force is large, the ratio of the change in the toe-in direction of the rear wheel according to the increase of the lateral force is increased.

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